The mechanics of such a move would be awkward for enterprise customers, some of whom have paid the Software Assurance annuity so that they can upgrade the Windows client without additional expense. But it could be done, Miller said.
"For enterprises, it's up to Microsoft to figure out ways to make customers understand the value of why they have Software Assurance," he said, giving a nod to the other benefits besides upgrades that Microsoft sticks in the program.
But what's in it for Microsoft?
Putting Windows on equal footing with other OSes, for one: Users have been trained to expect free operating system upgrades on their smartphones and tablets, and with Apple's move last year to give away OS X updates, those on Macs as well. Windows on the desktop is the holdout.
And by giving away Threshold, Microsoft would expect to see a much faster uptake — that's happened for Windows 8.1, and Apple's latest OS X, Mavericks — which would be a boon to developers, who could then focus more on the latest rather than supporting the older editions. If Microsoft offered free upgrades to Windows 7 customers, it would also have a shot at preempting a repeat of the XP problem, where millions ran the aged OS up to and beyond its support lifetime.
Nadella's demotion of Windows in his email also matches the expectations of Threshold, which reportedly will not be an ambitious release on the order of Windows 8. Instead, the upgrade will continue the work started in Windows 8.1 to make the OS more palatable to long-time customers who interact with systems using a mouse and keyboard. If accurate, Microsoft's retreat from touch will confirm what everyone already seems to know, but that the company has refused to publicly admit: Windows 8's radical changes were a failure in the marketplace.
The Nadella strategy email can be read on Microsoft's website.
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